OS1609 Constitutive Model for Temperature Dependence of Plastic Deformation of Shape Memory Alloys

2013 ◽  
Vol 2013 (0) ◽  
pp. _OS1609-1_-_OS1609-2_
Author(s):  
Akira NAGAI ◽  
Tadashige IKEDA
2013 ◽  
Vol 535-536 ◽  
pp. 105-108
Author(s):  
Xiang He Peng ◽  
Min Mei Chen ◽  
Jun Wang

A constitutive model is developed for shape memory alloys (SMAs) based on the concept that an SMA is a mixture composed of austenite and martensite. The deformation of the martensite is separated into elastic, thermal, reorientation and plastic parts, and that of the austenite is separated into elastic, thermal and plastic parts. The volume fraction of each phase is determined with the modified Tanaka’s transformation rule. The typical constitutive behavior of some SMAs, including pseudoelasticity, shape memory effect, plastic deformation as well as its effects, is analyzed.


2012 ◽  
Vol 2012 (0) ◽  
pp. _J044052-1-_J044052-3
Author(s):  
Akira NAGAI ◽  
Tadashige IKEDA ◽  
Le Truong ◽  
Masato NIWA

2012 ◽  
Vol 25 (3) ◽  
pp. 285-298 ◽  
Author(s):  
Xianghe Peng ◽  
Bin Chen ◽  
Xiang Chen ◽  
Jun Wang ◽  
Huyi Wang

Author(s):  
Francis R. Phillips ◽  
Daniel Martin ◽  
Dimitris C. Lagoudas ◽  
Robert W. Wheeler

Shape memory alloys (SMAs) are unique materials capable of undergoing a thermo-mechanically induced, reversible, crystallographic phase transformation. As SMAs are utilized across a variety of applications, it is necessary to understand the internal changes that occur throughout the lifetime of SMA components. One of the key limitations to the lifetime of a SMA component is the response of SMAs to fatigue. SMAs are subject to two kinds of fatigue, namely structural fatigue due to cyclic mechanical loading which is similar to high cycle fatigue, and functional fatigue due to cyclic phase transformation which typical is limited to the low cycle fatigue regime. In cases where functional fatigue is due to thermally induced phase transformation in contrast to being mechanically induced, this form of fatigue can be further defined as actuation fatigue. Utilizing X-ray computed microtomography, it is shown that during actuation fatigue, internal damage such as cracks or voids, evolves in a non-linear manner. A function is generated to capture this non-linear internal damage evolution and introduced into a SMA constitutive model. Finally, it is shown how the modified SMA constitutive model responds and the ability of the model to predict actuation fatigue lifetime is demonstrated.


2021 ◽  
Vol 1 (2) ◽  
pp. 12-20
Author(s):  
Najmeh Keshtkar ◽  
Johannes Mersch ◽  
Konrad Katzer ◽  
Felix Lohse ◽  
Lars Natkowski ◽  
...  

This paper presents the identification of thermal and mechanical parameters of shape memory alloys by using the heat transfer equation and a constitutive model. The identified parameters are then used to describe the mathematical model of a fiber-elastomer composite embedded with shape memory alloys. To verify the validity of the obtained equations, numerical simulations of the SMA temperature and composite bending are carried out and compared with the experimental results.


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